Nett T M, Pickett B W
J Reprod Fertil Suppl. 1979(27):465-70.
Two studies were conducted to determine the relationship between LH and progesterone and between PMSG and progesterone during pregnancy in mares. In the first, samples of jugular blood were collected daily from 7 mares from the first day of oestrus until Day 28 of pregnancy, and in the second, samples were collected weekly from 14 mares from Day 35 of gestation until parturition. In an attempt to prolong secretion of progesterone from accessory corpora lutea, 7 of these 14 mares were injected with increasing doses (2--10 mg) of diethylstilboestrol (DES) between Days 84 and 142 of gestation. The remaining 7 mares received injections of vehicle. Concentrations of LH, PMSG and progesterone in serum were determined by radioimmunoassay. From the onset of oestrus until Day 4 of gestation, serum concentrations of LH and progesterone were negatively correlated (r = 0.67, P less than 0.01), but from Days 5 to 28 a positive correlation (r = 0.80, P less than 0.01) was noted. Likewise, serum concentrations of PMSG and progesterone were highly correlated between Days 35 and 196 in mares injected with DES (r = 0.72, P less than 0.01) and the vehicle (r = 0.75, P less than 0.01). Injections of DES did not influence serum concentrations of LH, PMSG or progesterone, or affect the length of gestation. It was concluded that DES does not influence the maintenance of pregnancy in the mare.
进行了两项研究以确定母马怀孕期间促黄体素（LH）与孕酮之间以及孕马血清促性腺激素（PMSG）与孕酮之间的关系。第一项研究中，从7匹母马发情第一天至妊娠第28天每天采集颈静脉血样本；第二项研究中，从14匹母马妊娠第35天至分娩每周采集样本。为了尝试延长副黄体分泌孕酮的时间，在这14匹母马中，有7匹在妊娠第84天至142天期间注射递增剂量（2 - 10毫克）的己烯雌酚（DES）。其余7匹母马注射赋形剂。通过放射免疫分析法测定血清中LH、PMSG和孕酮的浓度。从发情开始至妊娠第4天，血清中LH和孕酮的浓度呈负相关（r = 0.67，P < 0.01），但在第5天至28天观察到呈正相关（r = 0.80，P < 0.01）。同样，在注射DES的母马（r = 0.72，P < 0.01）和注射赋形剂的母马（r = 0.75，P < 0.01）中，妊娠第35天至196天期间血清中PMSG和孕酮的浓度高度相关。注射DES不影响血清中LH、PMSG或孕酮的浓度，也不影响妊娠期的长度。得出的结论是，DES不影响母马妊娠的维持。
